I think Judy has given some good advice. And some babies just don't like to eat much upon waking. If your lo is like this, then you could offer half of the bottle and then the rest in a sippy with breakfast or as part of his meal, on cereal or whatever.
You could also try a small snack before bed, not so much as he will wake up the next morning still full from the night before. It may take a while until you start to see solids increase, and he is not drinking much more than the recommended amount anyway. It might be more of just playing around with the times that solids are offered.